The invention relates to a detector comprising a preamplifier having an input and an output, and a first comparator circuit having a first input, which is coupled to the output of the preamplifier, and a second input for detecting whether a detection voltage at the second input is exceeded by the voltage at the first input of the comparator circuit.
Detectors are for example used in recording amplifiers for magnetic recording in conjunction with a voltage-controlled amplifier, so as to reduce the gain of said amplifier when the amplitude of the signal exceeds a specific limit.
In known detectors the output signal of the preamplifier is applied to a half-wave or full-wave rectifier circuit via a coupling capacitor, so as to filter out the d.c. component. The rectified signal is applied to a comparator circuit.
Since capacitors with high capacitance values cannot be integrated, these capacitors, when the detector is incorporated in an integrated circuit, have to be connected externally. In order to limit the number of external connection points and the number of components to be connected, it is therefore desirable to avoid the use of coupling capacitors.